A work machine such as an agricultural tractor may be driven with motive force taking several different forms, such as a rear wheel drive, four wheel drive (4WD), mechanical front wheel drive (MFWD), track-type drive, etc. In the case of an MFWD equipped tractor, the front wheel drive typically is not full time, and an electronic switch in the operator's station is used to switch between rear wheel drive and MFWD mode.
An MFWD tractor may include an internal combustion (IC) engine which provides input power to a transmission, which in turn is coupled with and drives the rear axles through a rear end differential. The transmission may also include an output shaft, typically facing in the forward direction, which connects via a drive shaft or the like with the MFWD at the front end of the tractor.
An operator may order a new MFWD equipped tractor with a selected tire combination between the front and rear tires, or may desire to change to a different tire combination for some reason. Depending on the selected tire combination, the transmission may need to have a different gear ratio for the output shaft to the MFWD. Conventional transmissions with an output shaft for an MFWD typically do no allow the gear ratio to be easily changed, either during initial assembly or in a retrofit situation. It is thus necessary to use a different transmission with a different gear ratio, or disassemble the transmission and replace the gear set coupled with the MFWD output shaft. Either solution is not optimal for efficiency and cost.
What is needed in the art is a tractor with a transmission which may be modified to provide a different gear ratio to the MFWD output shaft, without having to completely disassemble or replace the transmission.